Vidas benchtop immunoanalyzer

The VIDAS Anti-HCV (bioMérieux) was used as the index test for the qualitative detection of antibodies to HCV. DBS specimens were punched (1 X 6 mm) using a pneumatic Dried Blood Spot Punch System (Analytical Sales and Services Inc.) Into 2 mL 96-well polypropylene plates (ThermoFisher Scientific). DBS punches were eluted in 100 µL of DPBS pH 7.4 containing 0.5% BSA and 0.05% Tween 20 at room temperature for 1 h with agitation (1000 rpm) as indicated above. Afterwards, all remaining DBS eluate was transferred into HCV Strips (bioMérieux) and processed by an automated VIDAS benchtop immunoanalyzer (bioMérieux). A test value < 1.0 and ≥ 1.0 was interpreted as negative and positive respectively unless stated otherwise. Test values (TV) were calculated as follows: TV = relative fluorescent value / background fluorescence value.

The VIDAS HIV Duo Quick (bioMérieux) was used as the index test for the qualitative detection of antibodies to HIV. DBS specimens were punched (1 X 6 mm) using a pneumatic Dried Blood Spot Punch System (Analytical Sales and Services Inc.) into 2 mL 96-well polypropylene plates (ThermoFisher Scientific). DBS punches were eluted in 200 µL of DPBS pH 7.4 containing 0.5% BSA and 0.05% Tween 20 at room temperature for 1 h with agitation (1000 rpm). The elution buffer is based on some of our previous work^{9 (link)}. The punching and elution protocol was carried out according to the Avioq HIV-1 Microelisa System package insert and took into consideration the minimal input volume for the VIDAS HIV Duo Quick test. Afterwards, all remaining DBS eluate was transferred into HIV6 Strips (bioMérieux) and processed by an automated VIDAS benchtop immunoanalyzer (bioMérieux). A test value < 0.25 and ≥ 0.25 was interpreted as negative and positive respectively unless stated otherwise. Test values (TV) were calculated as follows: TV = relative fluorescent value/background fluorescence value.